Arrangement for transmission of ultra short waves



July 14, 1936. M. VON ARDENNE ARRANGEMENT FOR TRANSMISSION OF ULTRA,SHORT WAVES v Fild June 19, 1931 Patented July 14, 1936 UNITED STATESPATENT OFFICE ARRANGEMENT FOR TRANSMISSION OF ULTRA SHORT WAVESApplication June 19, 1931, Serial No. 545,459 In Germany June 21, 1930 4Claims.

The subject matter of the present invention is constituted by anarrangement for the transmission of a plurality of ultra-short waves, orone or more ultra-short wave bands. As well known, ultra-short wavespermit only of transmission between places which are within visiblerange or practically within visible range of each other. For this reasonit is necessary, for the transmission of ultra-short waves overrelatively long distances, to provide intermediate arrangements, whichare arranged in elevated position for the purpose of ensuringtransmission to the next station, and are furnished with an intermediatereceiver by which an intermediate transmitter is controlled. Sincearrangements of this description are also essential in the transmissionof one single ultra-short wavelength, a plant of this kind would not besufficiently productive. This was a promoting factor which suggestedthis invention, and which, therefore, has the object of rendering theseries of intermediate arrangements suitable for the transmission of aplurality I of ultra-short waves. For various reasons, and moreparticularly on account of secrecy of the messages, considerably lessconsumption of energy and a more favourable technical form, the receiverand transmitter are furnished with reflectors, which pick up theradiated waves, or transmit the waves respectively. For transmissionover relatively long distances the intermediate arrangements abovereferred to would accordingly be furnished with a receiving reflectorand a transmitting reflector, between which there is arranged thetransmission device. Now it is not immediately possible to provide forthis purpose an amplifying arrangement of any kind, as transmission of aplurality of substantially different ultra-short waves would in thismanner naturally be impossible, and even the transmission of a narrowfrequency band would be prevented by reason of the high selectivityproduced by the large number of intermediate stations necessary forrelatively long distances.

According now to the invention, there are employed for transmitting afrequency band, resonance amplifiers which are slightly relativelydetuned, so that the effective resonance curve is provided with asufficient width of frequency, and therefore amplification of theparticular frequency band, or a plurality of ultra-short wavesrespectively, is thus rendered possible.

A such arrangement does not suffice for the transmission of a pluralityof ultra-short waves which differ very appreciably from each other,

or for relatively wide frequency bands. For this reason according tothis invention semi-aperiodic amplifiers are employed in instances ofthis kind,

i. e., amplifiers which possess poor-capacity chokesv in their anodecircuit. According to the 5 present invention the transmission range ofan intermediate chain of transmitters of this kind may be extended to avery wide frequency range by the use of wholly aperiodical amplifiers,the technical execution of which has more recently 10 been renderedpossible by the use of amplifier structures of very poor capacity havinghighly emissive cathodes.

The intermediate receivers and intermediate d transmitters may, inaccordance with the invention, be connected by a plurality of preferablyparallel arrangements tuned to different frequencies, and the resonancefrequencies distributed in suitable manner over the range to betransmitted. For this purpose, according to the 20 invention, there areprovided a plurality of correspondingly-differently tuned dipoles in there fiectors.

In the accompanying drawings Fig. 1 shows diagrammatically arepeating-station according to the invention with a receiver, atransmitter and the amplifier arranged between both.

Fig. 2 shows a complete arrangement with transmitter, receiver andamplifier.

l is a parabolic reflector, in the straight lines of focus of which aredisposed the dipole wires 3 and 4. These wires are connected by leads 5with a non-improved or even strongly attenuated oscillatory circuit 6,which, with the provision of a biasing potential battery 8, is locatedbetween the cathode and the control grid 9 of an amplifying tube 1. Thecathode of this amplifying tube, in similar manner to that of the secondtube I9, is heated by a heating battery. The anode I I leads over ahighly resistive element 12 of, say, 2000 ohms to the positive batterypole of the anode potential source l3, which is joined by its other poleto the cathode of the tube. The oscillations of potential occurring atthe anode I l are passed over a condenser It to the control grid 20 ofthe tube I9, this grid receiving the necessary negative bias potentialfrom the grid battery l8 via a leakage resistance l1. Both tubes arepreferably constructed as screening grid tubes, where- 50 by thescreening grids, in a preferred form of embodiment, may be connectedwith each other, and, in relation to the cathode, receive a positivepotential from the battery I l. The anode 22 of the second tube I9 isconnected, via an oscillatory circuit 23, which is similar to thecircuit 6, i. e., is not improved or may even be strongly attenuated,with the positive pole of the anode potential source l3. From the endsof the oscillatory circuit the leads 24 pass to the dipole wires 25 and26, which are provided within the radiating parabolic reflector 2,preferably in the straight line of focus.

In the case of such intermediate arrangements it is absolutely essentialto prevent a back-coupling from the intermediate transmitter to theintermediate receiver assigned thereto. This, according to theinvention, may be accomplished by suitable construction and arrangementof the reflectors.

Since for the reasons above stated directional transmitters andreceivers are employed, it is absolutely essential in transmission overrelatively long distances that the stations are in permanent location.In the transmission over seas, lakes, etc. difiiculties are encounteredin this connection. To ensure the necessary non-rocking position at sea,the intermediate arrangements are mounted in elevated fashion on largeplates, which are carried by the long rods of supporting members,preferably hollow members. The supporting rods extend to such depth intothe water that the movement of the latter, which takes place principallyat the surface, has no influence on the position of the supportingplate, and accordingly that of the reflectors. These arrangements areanchored to the bed of the sea.

Fig. 2 illustrates the whole arrangement of the transmitting-system. Therepeating device consists of the repeating receiver 39 and. therepeating transmitter 4| being coupled by means of an amplifier system40, operating substantially aperiodically. The entire repeating device39, 40, 4| is arranged at a suitable place between the transmitter 38and the receiver 42. For bridging greater distances, several repeatingdevices of a suitable number and with a suitable directional effect maybe arranged at suitable places between transmitter 38 and receiver 42.Several amplifier arrangements being dimensioned for the amplificationof different frequency-bands or being tuned to difierent frequencies,may be employed in parallel for the connection between repeatingreceiver 39 and repeating transmitter ll, instead of one singleamplifier-arrangement 40.

I claim:

1. In a system for transmitting ultra-short waves over long distances bymeans of repeating stations, a repeating station comprising aunidirectional receiving antenna, a similar retransmitting antennaradiating in a practically opposite direction and amplifiers connectingsaid antennas directly, said amplifiers being deturned relatively toeach other.

2. In a system for transmitting ultra-short waves over long distances bymeans of repeating stations, a repeating station comprising aunidirectional receiving antenna, a similar retransmitting antennaradiating in a practically opposite direction and amplifiers connectingsaid antennas directly, said amplifiers being broadly tuned.

3. In a system for transmitting ultra-short waves over long distances bymeans of repeating stations, a repeating station comprising aunidirectional receiving antenna, a similar retransmittlng antennaradiating in a practically opposite direction and amplifiers connectingsaid antennas directly, said amplifiers being detuned relatively to eachother, said amplifiers being coupled aperiodically.

4. In a system for transmitting ultra-short Waves over long distances bymeans of repeating stations, a repeating station comprising aunidirectional receiving antenna, a similar retransmitting antennaradiating in a practically opposite direction and amplifiers connectingsaid antennas directly, said amplifiers being broadly tuned, saidamplifiers being coupled aperiodically.

MANFRED VON ARDENNE.

